Edging machine



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EDGING MACHINE Filed Aug. 5, 1962 6 Sheets-Sheet 6 United States Patent 3,210,890 EDGING MACHINE William A. Lannom, Blue Island, 111., assignor of onehalf to Edgar J. Schroth, Blue Island, Ill. Filed Aug. 3, 1962, Ser. No. 214,739 34 Claims. (Cl. 51-101) This invention relates to edging machines and particularly to a machine of novel, improved construction for forming a bevelled edge on the periphery of articles such as ophthalmic lenses.

Such machines conventionally comprise a rotatably supported abrading wheel and an overlying head supported to swing about a horizontal axis located to one side of the abrading wheel. The free end of the head rotatably supports a spindle adapted to hold the lens so that it may be carried by the weight of the holder into edge contact with the periphery of the abrading wheel. The spindle also supports a former or pattern having the shape to which it is desired that the lens be edged. Associated with the pattern is a shoe which when engaged by the pattern closes a circuit to a motor adapted to turn the spindle and thereby the lens and the pattern. At the initial engagement of the lens with the periphery of the abrading wheel, the pattern is out of engagement with the shoe and the motor does not operate. However, as soon as the portion of the lens edge presented to the abrading wheel has been ground to a size which allows the pattern to engage its shoe, the motor is energized and turns the lens just sufficiently to present a new edge portion of the lens to the abrading wheel which raises the pattern away .from the shoe so as to open the circuit to the motor and stop further rotation of the lens. The thus controlled stopping and starting of the lens continues until the lens has completed a full revolution. Commonly, the lens will be allowed to complete one or more further revolutions in order to produce a more finished edge on the lens periphery than results in the initial rough edging.

A principal object of the present invention is to provide a novel and improved edging machine for ophthalmic lenses and the like employing the aforesaid principles but which will do so more effectively and efficiently, and at the same time will be of a simple, compact construction economical to manufacture and also will require a minimum amount of skill and attention to operate.

In keeping with this object a first and important feature of the invention is the employment of a pair of abrading discs each having a frusto-conical shaped periphery. The two discs are arranged in juxtaposed spaced concentric relation so that each disc grinds only one side of the bevel, and are so mounted as to rotate in opposite directions about an axis which is inclined at a relatively sharp angle to the horizontal axis of the lense supporting spindle. The angle of inclination is selected in accordance with the diameter of the two discs that, in top plan, the periphery of the two discs will approximate an ellipse corresponding in curvature close to the base curvatures of the ordinary and many of the extraordinary ophthalmic lenses. Therefore the edging action can be made to follow the curvature of the lenses and, since the pressures exerted on the lens edge by each disc are counteracted by the pressure exerted by the oppositely rotating other disc, the effect of varying degrees of hardness in the glass is minimized. Lens breakage is reduced and a more efiicient bevelling action is obtained.

In accordance with the invention, the effectiveness of the beveling action is further promoted by shortening the radius through which the lens is free to turn about its horizontal axis so as to approximate the radius of the abrading discs and by providing means for adjusting the force by which the lens is fed into the periphery of the abrading discs rather than relying entirely on gravity.

The invention also contemplates novel means for applymg coolant to the abrading discs in a manner which avoids spattering and/ or splattering of the operater.

It also contemplates means by which the frusto-conical surfaces of the abrading discs may be trued and their angular relation accurately maintained.

A further object and particularly important feature of the invention is the provision of novel means by which operation of the machine, once initiated, will be caused to automatically conduct the lens through the rough and fine edge grinding steps and at the completion of the edging cycle will drive the head to a raised position suflicient to locate the lens out of the reach of the abrading discs and in a position where it will be convenient to remove the edged lens and insert a new lens for edging.

For accomplishing this, the invention utilizes a cam wheel which is mounted to turn about an axis coinciding with the axis about which the head is rockable. This cam wheel is drivingly connected to the motor which turns the lens spindle but the gearing which permits this is selected so that the cam wheel turns at a slower rate than does the lens. For example, it may be so arranged as to complete a full revolution for each two or three revolutions of the spindle. The cam wheel is provided with a notch in its periphery so that a cam follower which is pivotally mounted on the head to follow the periphery of the cam wheel will catch in the notch as the cam completes one full revolution. This corresponds to the end of the edging cycle performed on the lens. Means are provided under the control of the follower so that the motor can continue to operate with the pattern out of engagement with the shoe. Consequently as the cam wheel turns, it rocks the head so as to raise its lens spindle supporting end away from the abrading discs.

In accordance with the invention, means are provided which are actuated by the head when it has been rocked to a suflicient height to shut off the motor. Means are also provided in the form of a latch arm pivotally connected to the forwardvend of the head. This latch arm has a notch adjacent its free end which engages with a catch as the head is raised to its inoperative position. The latch arm serves first to limit the extent of upward rocking of the head and in this respect has a cooperative function with the mentioned third switch. It also provides a means of locking the head in its raised or inoperative position. This represents a further feature and/or object of the invention.

Still another important feature of the present invention is the association of such locking means with the lens size control wheel which controls the height of the contact shoe so that the head can be unlocked after moving into its raised inoperative position at the completion of the edging cycle only by setting the control wheel for a maximum lens size. This has the advantage that it minimizes the opportunities for edging a lens to a too small 'sizebecause of failure to reset the size control wheel.

After completing one edging cycle, the machine can'- not be sent through a second edging cycle until and unless the operator unlocks the latch arm by adjusting the lens size control wheel into the range of high lens size. Alternatively, means are provided whereby the size control wheel is automatically turned to a high lens size setting as the carriage is raised to its inoperative position at the completion of the edging cycle. Ineither instance, therefore, where the machine is used to successively edge two differently sized lenses, if the operator neglects to reset the size control wheel, the only result will be that he has edged the second lens too large and it will need to be re-edge-d to the correct size. Without such a control, if the second lens were to be of larger size than the first, such carelessness on the part of the operator would mean loss of the lens blank.

Other features and/ or objects of the invention include a novel construction of pattern holder wherein the pattern is magnetically supported on the end of the lens spindle so as to simplify the mounting and replacing of patterns.

The invention also contemplates new and improved means for adjusting as well as limiting the amount of swing of the lens about a vertical axis to accommodate centering and/ or other location of the apex of the bevel relative to the two surfaces of the lens.

The invention also contemplates novel structure for supporting the optical head and which may be conveniently adjusted to accommodate for wear of the abrading discs.

Many other objects, advantages and/or features of the invention will be apparent, or will become so, from the detailed description of a preferred embodiment of the invention which will now be described.

Therefore, referring now to the drawings wherein like parts are identified by like reference numerals;

FIGURE 1 is a side elevati-onal view of an edging machine constructed in accordance with the present invention;

FIGURE 2 is a top plan view of the machine;

FIGURE 3 is an elevat-ional view partially in section taken through the base along lines 3-3 of FIGURE 2 and looking in the direction indicated by the arrows;

FIGURE 4 is a sectional view taken along lines 4-4 of FIGURE 2 looking in the direction indicated by the arrows;

FIGURE 5 is a more fragmented view generally similar to FIGURE 4 showing an alternative construction;

FIGURE 6 is a rear elevational view of the device, partly in section, taken along lines 66 of FIGURE 2;

FIGURE 7 is a vertical sectional View taken through the head along lines 77 of FIGURE 2;

FIGURE 8 is a fragmented view, partly in section, and illustrates the relation of cam and latches when the optical head is in its raised position out of reach of the abrading discs;

FIGURE 9 is a section-a1 view taken along lines 99 of FIGURE 3 to show details in construct-ion of the abrading means;

FIGURE 10 is a schematic sketch of the electrical circuit of the machine;

FIGURE 11 is a fragmented top plan view illustrating the truer in position on the front wall of the base, the stone being retracted from the surfaces of the two abrading discs for convenience in illustration;

FIGURE 12 is a vertical sectional view taken through the truer;

FIGURE 13 is a fragmented view in side elevation; and

FIGURE 14 is a front elevational view also fragmented which illustrate a modification of the size control mechanism.

Referring now to the several views and first to FIG- URES 1, 2 and 3, the present invention is illustrated as embodied in a machine having a base indicated generally at which serves as a support for abrading means indicated generally at 122. Said abrading means comprise a pair of adjacently -loc-ated concentric discs 24 and 26 supported for rotation about an inclined common axis and in opposite directions. For example, disc 24 may turn clockwise while disc 26 turns counterclockwise. As illustrated best in FIGURE 3 considered with FIGURE 9, base 20 has a side wall 28 to which a mounting block or support 30 is welded or otherwise secured. Said supporting block 30 has an inclined planar surface at 32 and a central bore 34 the axis of which is disposed at right angles to its planar surface -32. Fixed within bore 34 is a shaft 36 about which are assembled a pair of spool pulleys 38 and 40 one being disposed within the other. The outer pulley 38 has an integral flanged portion at 42 provided with a recess 43 on which is seated the inner periphery of abrading disc 26. The opposite side of said inner periphery of abrading disc 26 is recessed at 44 to receive the outer portion of a mounting ring 46 which is secured to flange 42 as :by screws or the like 48, thereby clampingly securing the abrading disc 26 to pulley 38. Correspondingly inner pulley 40 also has a flanged portion 50 to support abrading disc 24. Its flanged portion 50 is recessed at 52 in which seats the inner periphery of the abrading disc 24, the latter being held in place by a mounting ring 54 connected to flange 50 as by screws 56. Each of said pulleys is also provided with driving flanges at the opposite end grooved to receive appropriate drive belts. Whereas drive flange of pulley 38 is preferably formed integrally therewith, for convenience in assembly, the belt groove bearing flange 62 of the inner pulley 40 is formed as a separate piece and is threadedly connected thereto as at 64. Radial thrust bearings are provided at 58 to accommodate the rotary movement of pulley 38 about pulley 40 which in turn is rotated about shaft 36 in a counter direction. A horizontal thrust bearing 66 is also located between bearing 58 and flange 62. Mounting ring 46, advantageously, has a thickness less than that of the receiving recess 43 in flange 44 of pulley 38. This permits flange 62 to be tightened on its threaded connection 66 sufficiently to draw the two abrading discs into juxtaposed relation, any roughness in their initially contacting surfaces 24a and 26a being worn off in the first few revolutions of said discs so that their adjacent surfaces 24a and 26a are ground to an extremely smooth, fine texture and juxtaposed close, parallel relation. A lock nut is provided at 68 to complete the assembly of the two pulleys and a thrust bearing is located between said lock nut and surface 32 of support 30 to reduce friction. The two pulleys are -locked in place on shaft 36 as by means of a ring 70 fitted over the upper end of the shaft having a set screw 72, the end of which enters an appropriately located notch or groove 74 in the end of shaft 36. The opposite or lower end of shaft 36 is preferably threaded to receive a nut 76 which completes the assembly. Desirably, shaft 36 may be provided with a smal l bore 78 running axially thereof and provided with appropriately spaced communicating ports .for lubricating the contacting inner surface of pulley 40 and outer surface of shaft 36. The tWo pulleys may be driven from a single motor by m ans of belts 80 and 82 if one of said belts is crossed.

Rear wall 86 of base 20 serves as a support for a lens head supporting column indicated generally at 88. Referring therefore to FIGURES 4 and 6, column 88 comprises a main upright 90 bolted as at 92 or otherwise rigidly fastened to a mounting plate 94 having aligned grooves 96 through which extend bolts 98 securing said plate 94 to wall 86. Loosening bolts 98 accommodates movement of plate 94 so that the supporting column 88 may be laterally adjusted for centering the lens L over the abrading discs 24, 26 as will hereinafter be made clear. A scale may be provided on plate 94 as at 100 which cooperates with an index 102 on wall 86 to indicate the position of the plate 104 and thereby the extent of movement of column 88 in any lateral adjustment thereof.

Referring now more particularly to FIGURE 4, supported about the upper end of main support 90 is a cylinder 104 having reduced end portions 106 and 108 to which are threadedly connected an upper pivot bearing member 110 and a lower pivot bearing member 112. A lock nut 114 threadedly connected to the lower end 108 serves to prevent loosening of pivot bearing member 112 on said end 108. Means are also provided to secure cylinder 104 on upright 90 and to support its pivot bearing members 110 and 112 at a predetermined although adjustable height. Such means comprise an adjustment member indicated at 118 having a main stem 120 threadedly connected into an internally threaded bore 126 of the main stem 90. Said adjustment member 118 has an externally located head at 122 and an inwardly spaced flange 124 which seats between the upper end 106 of cylinder 104 and collar 116. Collar 116 is tightened on the threaded upper end 106 of the cylinder 104 so that the cylinder 104 is supported by flange 124. By turning head 122, stem 120 may be threaded into and out of bore 126 in upright 90 to adjust the height of the pivot supporting members 110, 112. Usefully, lock nut 114 is provided with a threaded bore into which is threadedly connected a set pin 128. The inner end of said pin engages within a key way 130 provided longitudinally of the main support 90 to inhibit turning of cylinder 104. Pin 128 also cooperates with flange 124 to hold cylinder 104 at an adjusted height on upright 90.

Referring now to FIGURES 1 and 2, a mounting plate 134 is pivotally connected between pivot bearing supports 110, 112 as by pin or pivot means 136 so that it is free to turn about a vertical axis indicated by lines VA-VA. Rigidly attached to the ends of said mounting plate 134 in appropriately provided recesses as by screws or other connecting means are a pair of parallel bearing plates 138, 140. The forward ends of these plates 138, 140 are provided with aligned openings through which extends a two part shaft indicated generally at 142. Said shaft 142 supports an optical head indicated generally at 144 so that it may pivot about a horizontal axis HAHA which saidshaft 142 defines and also about the previously mentioned vertical axis VAVA, the latter being disposed somewhat rearly of axis HAHA as defined by pivot pins 136, 136. As previously suggested, shaft 142 comprises a relatively long shaft part 146 and a shorter shaft part 148 the adjacent inner ends of which interfit so that together they serve as a pivotal support for the optical head 144. At the same time they are also free to rotate independently of each other for reasons as will hereinafter be made clear. Optical head 144 is of a generally U-shape and comprises a relatively wide leg portion 150 and a narrower leg portion 152 which lie above and straddle the high point of the abrading discs 24, 26. The inner and outer side walls of the narrower leg 152 are provided with openings adjacent their forward end which constitute bearings for a spindle 154 extending through said walls and parallel to shaft 142, its end protruding into the space between the two legs being provided with a resilient lens engaging pad 156. The longer leg 150 also supports a second spindle 158 having one end protruding through a provided opening in its inner wall and which end also is provided with a resilient lens engaging pad 162. A hearing plate 160 is provided for rotatably supporting the opposite end of spindle 158. Aligned with spindle 158 and coupled thereto as by a slip connection 168 is a retractable shaft 164 threadedly connected into the outer wall of said leg 150 as at 166. The outer end of shaft 164 has a handle 170 by which shaft 164 may be threaded inwardly or outwardly in its connection 166 so as to draw spindle 150 and its lens engaging pad 162 toward and away from lens engaging pad 156 of the first spindle to permit positioning and/ or removal of a lens blank therebetween. Instead of the indicated resilient lens engaging pads 156, 162, any other type of lens holders as are well known to the art, may be utilized.

Bearing plates 138, 140 also have portions extending rearwardly of supporting plate 134. These are suitably apertured at 171 and 172 to provide bearings for a shaft 173 disposed rearwardly of plate 134 and in parallel relation to'shaft 142. Below said shaft and rigidly secured to the rear side of mounting plate 134 are a pair of rearwardly protruding plates 174 and 178, which support a motor 176. At 182 is a bearing in plate 178 which rotatably supports motor arbor 184 and at 180 is a bearing which rotatably receives shaft 173. Motor 176 is adapted by means of suitable gearing to turn a lens L when supported between lens engaging pads 156, 162 at the ends of spindles 154, 158. Referring to FIGURE 2, arbor 184 of motor 176 has a gear 186 which meshes with gear 188 on shaft 173 so as to turn gear 190 on longer shaft part 146 of shaft 142 so as to simultaneously turn gears 192 and 194. Gear 192 meshes with gear 196 which engages with gear 198 to turn spindle 158. Simultaneously gear 194 meshes with gear 200 which engages with gear 202 to turn spindle 154. Because of the slip connection 168 between spindle 158 and retractable shaft 164, the latter does not turn.

When lens L is properly positioned between the lens engaging pads 156 and 162, its geometrical axis will correspond with the axis of spindles 154 and 158, and its peripheral edge will be disposed between the frusto-conical abrading surfaces 204, 206 of the abrading discs 24, 26 respectively at the high point of said discs. Preferably the axis of lens supporting spindles 154, 158 indicated by LA-LA (FIGURE 2) does not exactly intersect the axis about which the abrading disc rotates, but will be offset rearwardly therefrom by approximately 5 degrees. This has been found helpful to avoid lens chattering during the edging operation. As previously noted, the two abrading discs 24, 26 rotate in opposite directions so that the frictional drag of one abrading surface on the edge of the lens in the bevelling action is counteracted by the frictional drag of the other disc on the opposite side of the bevel so that the edging operation proceeds smoothly and efficiently, substantially unaffected by hard spots or other non-uniform textures occasionally found in the glass. As previously mentioned the shaft 36 and thereby the axis about which the abrading discs 24, 26 rotate is inclined at a relatively sharp angle with respect to the axis LA-LA about which the lens is turned. In practice, it has been found that the angle between the two axes should approximate 35 degrees, that is shaft 36 should be disposed at approximately 55 degrees to the horizontal where discs of approximately 6 inch diameters are used, the upper disc 24 having a somewhat smaller diameter which accommodates grinding the desired bevel in the lens edge. At the indicated angle of inclination the surfaces 204, 206 of the abrading discs define a curvature which when considered in the area of contact with the lens periphery very closely approximates the base curvatures of the usual range of ophthalmic lenses. The angles of inclination of cutting surfaces 204, 206 of the abrading discs 24, 26 are determined by the bevel which is to be ground on the lens edge. In practice it has been found that the included angle between the two sides of the bevel should be in excess of The presently preferred angle is approximately This is obtained by inclining surface 206 approximately 10 from the perpendicular to the axis of disc 26 and inclining surface 204 of disc 24 approximately 5 from parallel with its axis. Obviously when properly mounted, lens L will be disposed with its concave side directed toward the high end of the axis about which the abrading discs turn and its geometrical axis will correspond to the axis LA-LA about which spindles 154, 158 turn. Preferably axes LA--LA and that about which the abrading discs turn do not exactly intersect but the former is located approximately 5 to the rear of a horizontal plane which would include the axis of the abrading discs. This serves to minimize chattering. Moreover, it has been found that best results are obtained in the edging operation when the distances between the lens supporting spindles and the horizontal and vertical axes about which the lens swing are kept to a minimum length. Particularly good results have been obtained where the supporting head 144 has been so dimensioned that its axis HAHA, which shaft 142 defines, lies in a vertical plane approximately intersecting the outer edge of the abrading discs. This means that the lens will be fed into the cutting edges of the abrading discs by swinging about a horizontal axis approximately equal to the radius of the abrading discs. Vertical axis VA-VA about which the lens supporting head also swings in the edging operation is for practical reasons disposed rearwardly of axis HAHA. However advantageously it may be disposed much closer thereto than is illustrated in the example of FIGURE 4. For example in FIGURE 5, pivot bearing members 110 and 112 have been replaced by longer pivot bearing members 110' and 112' which extend forwardly of plate 134 and plate 134 has been provided with forwardly projecting pivot bearing plates 134a and 134b, plate 134a being pivotally connected to member 110 and plate 13412 to member 112 by connection means 136 which define a new horizontal axis VAVA' about which head 144 may swing. This axis is located to the forward side of the supporting plate 134 and considerably closer to axis HAHA.

As is conventional, means are provided for starting and stopping rotation of the lens so that the lens blank may be edged to a particular shape. Such means, in accordance with the present invention, comprises a former or pattern 288 selected to have the shape to which it is desired that the lens be edged and is non-rotatably mounted on the end of lens supporting spindle 154 so as to turn therewith and to be fed into and out of engagement with a contact shoe 218 as the lens is rocked about axis HAHA. Referring to FIGURE 1 the outer end of spindle 154 is shown provided with a reduced cylindrical end section 210 over which the suitably apertured pattern 208 seats. The end of spindle 154 is also provided with outwardly projecting pins 212 spaced about section 210 and which engage in provided openings of the pattern. These serve to properly align the pattern and to prevent its turning on section 210. Magnets 216 in the end of shaft 156 serve to attract and hold the pattern in place. Where the pattern selected is of synthetic resin or other non-magnetic attractile material, a ring of magnetic metal may be placed over the outside of the former 208 which will be attracted by the magnets to hold tthe pattern in place. Contact shoe 218 comprises a normally open switch 220 and is closed by engagement of the former 208 with arm 222 which is pivotally connected at one end and spring tensioned so as to be normally free of the switch. As indicated in FIGURE 10, closing of switch 220 serves to complete a circuit to motor 176. Said circuit comprises a line 224 which connects one side of the motor to a source of electrical power, the other side of the motor being connected by line 226, normally closed switch 228, line 230, the aforementioned normally open switch 220 and line 232 to the aforementioned electrical power source. It will thus be evident that as the lens periphery is initially brought into engagement with the frusto-conical surfaces 204, 206 of the abrading discs, pattern 208 will be held by spindle 154 out of engagement with switch operating member 222. Switch 220 is therefore open and motor 176 is deenergized so that the lens does not turn. As the abrading discs grind the contacting edge of the lens, it is fed toward the disc by the force of gravity which rocks head 144 about shaft 142 (axis HAHA). At some stage, enough of the lens edge will have been ground off in forming the bevel to carry the pattern 208 into engagement with arm 222 to close switch 220. This will complete the circuit aforementioned and the motor 176 will start to turn the lens spindles 154, 158 through the gearing above described. This will cause the immediately adjacent and unground portion of the lens periphery to be presented to the abrading edges of discs 24, 26. Head 144 will be rocked upwardly about shaft 142 and pattern 208 will be raised out of engagement with contact shoe 218. Switch 220 therefore opens and motor 176 stops further turning of the lens until this portion of its periphery has also been ground to where the pattern will again engage the contact shoe to close switch 220 and repeat the process. This starting and stopping rotation of the lens continues until the lens has made a complete revolution, at which time it has been ground to the desired shape and size. Because of the edging procedure followed, it will be appreciated that what in effect is formed on the periphery of the lens is a series of small adjacent scallops. conventionally, therefore, the lens is turned through one or more further revolutions to minimize the scalloped effect.

Means are also provided by which the size of the lens may be varied in the edging process. Referring to FIG- URE 1, contact shoe 218 is mounted on the upper end of a member 234 which is arranged so as to be vertically slidable in the bore of cylindrical portion 236 of member 238. Said member 238 is supported at one end of piece 246 which is fixed to the lower end of mounting plate 134 so as to swing with head 144 about vertical axis VAVA or VAVA' but not about axis HAHA. As seen best in FIGURE 3 the lower end of member 238 is bifurcated to locate a cam 242 mounted on a shaft 240 having an externally located hand wheel 244 associated therewith. The lower end of member 234 rides on the periphery of cam 242 so that by turning wheel 244 contact shoe 218 may be raised or lowered. The spacing of contact shoe 218 from pattern 208 controls the size to which the lens will be ground in the bevel-edging process. As illustrated in FIGURE 2, hand wheel 244 is provided with a scale 246 and member 238 is provided with an index 248 cooperating with said scale 246 which has been related to the varying diameter of cam 242 whereby it indicates the size of lens to which a lens will be ground at the height to which the contact shoe 218 is adjusted.

As already pointed out, in the edging operation it is highly desirable that the lens be turned through more than one revolution in order that it may be first edge ground to desired size and then its edge finely ground to a desired finish. The invention also contemplates means for automatically raising the lens out of the reach of the abrading discs at the completion of the edging cycle. Such means utilize motor 176 to rock the lens spindle supporting head 144 about shaft 142 so that the upward movement of the lens to an out-of-reach inoperative position is positive and secure.

Turning therefore to FIGURE 2, FIGURES 1 and 7 being considered in conjunction therewith, rock shaft 142 as previously described, includes a smaller shaft 148 in addition to the longer shaft portion 146 on which is supported gearing through which rotary motion of the motor 176 is transmitted to turn lens supporting spindles 154, 158. Said smaller shaft portion 148 is provided with a cam wheel 252 having a V-notch in its periphery at 254 (FIGURE 7) and is arranged to be turned by motor 176 as it turns the lens supporting spindles 1-54, 158, although not at the same rate. For this purpose, a large gear 256 is mounted at the outer end of shaft 148 which meshes with a smaller gear 258 on the end of shaft 173 (FIGURE 2) which is driven by motor 176 through meshing gears 186 and 188 as aforedescribed. The diameters of gears 256 and 258 are so selected that shaft 148 will be rotated at a rate substantially slower than the rate at which the lens L is turned. Preferably their diameters are so arranged that cam 252 will make but one revolution each time the lens L is rotated three times, this corresponding to the number of revolutions required of the lens to complete its one rough edge grinding and two finish grinding operations in the edging cycle. If only one finish grinding operation is required, then the ratio between the gears 256 and 258 will be 2 to 1, or any other ratio dependent on the number of revolutions required of the lens L to complete the edging operation. For example, if only the rough grinding step were required, then the diameter of gears 256 and 258 would be in a 1 to 1 ratio.

Turning now to FIGURES 1 and 7, on the top side 260 of the optical head 144 is a lever arm 264 pivotally connected intermediate its ends as by means 262. On the under side of the end of lever 264 disposed to the rear of shaft 148 a portion 266 is atfixed which protrudes through a provided opening 268 in said top side 260 so as to ride the periphery of cam wheel 252 (FIGURE 7) and to drop into notch 254 as the cam wheel 252 completes a full revolution (FIGURE 8). Since the cam wheel 252 is turning in clockwise direction and at this stage in a downward direction away from a vertical plane including axis HAHA of shaft 148, further movement of the cam wheel will impart a rocking movement of head 144 about 9 shaft 142 (axis HAHA) so as to raise the lens L away from surfaces 204, 206 of the abrading discs 24, 26. This is on the assumption that motor 176 continues to operate. However, as aforementioned the operation of motor 176 is interrupted when the former 208 is raised out of engagement with contact shoe 218. In order that the motor 176 will continue to operate after it has turned cam Wheel 252 sufliciently to rock head 144 so that pattern 208 is lifted out of engagement with contact shoe 218, a second normally open switch 268 is provided in parallel with switch 220 of the contact shoe (FIGURE 10). This second switch is located on the under side of the optical supporting head 144 and adjacent its rear end so as to be actuated by a rod 274 provided in a bore 276 in the rear wall 270 of head 144. Referring to FIGURES 7 and 8, rod 274 has an upper end which protrudes above the surface of the optical head so as to be engaged by portion 282 of lever 264 as its portion 266 drops into and is caught by notch 256 of cam wheel 252. The lower end of rod 274 rides on a roller 278 carried by a tensioned spring 280 operatively associated with switch 268. Therefore as the oam follower or portion 266 is caught by the notch or recess 254 in cam 252 the rod 276 is forced downwardly .by end 282 of lever arms 264 against rollers 278 causing spring 280 to close switch 268. Motor 176 therefore continues to operate even after switch 220 has been opened by movement of the former 208 away from shoe 218 in the rocking of the forward end of head 144 away from the abrading discs 24, 26. A capacitor 284 connected across the circuit in parallel with said two normally open switches 220 and 268 serves to prevent arcing between the contacts in the operation of switch 268. Motor 176 therefore continues to rotate cam wheel 252 as well as the lens supporting spindles so that the forward end of head 144 is rocked upwardly about shaft 142 as a downward force is exerted on portion 266 caught in notch 256 of the cam wheel 252.

As previously mentioned, in series with normally open switches 220 and 268 is a normally closed switch 228 (FIGURE 10). This switch is mounted on the rear side of mounting plate 134 and is in a position to be actuated by means of a spring bearing roller 230 which engages the rear side of the optical head. 144. Said rear wall acts on roller 230 to open switch 228 as head 144 has been rocked about shaft 142 through an angle suflicient to locate the lens supporting spindles at a height where lens L will be out of reach of the abrading discs. Motor 176 is thereupon deenergized and further rotation of the lens and its supporting spindles stops until the head 144 has been again lowered to a position where the lens engages the abrading discs and the pattern contacts shoe 218. To disengage portion 266 from the notch 256 in cam wheel 252, the operator will grasp the head 144 by means of handles 294 and press downwardly on the outer or free end 286 of latch lever 264. The optical head may be thereafter held in said inoperative raised position as for example to permit removing the lens L and/ or replacing it with a new lens to be edged by catching portion 288 of lever 290 pivotally connected to the aforementioned means 262 in the provided opening 296 of catch 298. Preferably adjustable means are provided at 300 which engage on the upper surface of the lever 264 so as to hold lever 290 in a position such that its portion 288 will be disposed above catch 298 in the various positions of the optical head 144 as it swings about axis HA--HA of shaft 142.

However, in accordance with the present invention, locking means are also provided whereby once the optical head has been raised to its inoperative position it will remain locked in said position and portion 266 cannot be withdrawn from notch 256 of the cam wheel 252 because the optical head cannot be manually rotated about axis HAHA the small additional distance until said means are released. This locking means is associated with the lens diameter or size controlling mechanism before described to serve the useful purpose of minimizing lens loss as a result of an operator forgetting to reset the lens size diameter control between lens edging operations. For example, without the arrangement about to be described, it would be entirely possible for an operator after edging a 38 mm. lens to a particular shape to merely remove the edged lens, replace it with a second blank, and restart the edging operation. If the second lens were to be edged to say a 40 or 42 mm. size, the blank would have been ground too small and would have to be discarded. However, in accordance with the present invention, a latch arm 302 is pivotally connected at its upper end to the forward end of optical head 144 as at 303. The for ward edge 310 of arm 302 is smooth except for a notch 312 located intermediate its two ends but closest to its free end. Pivotally connected to contact shoe supporting member 238 is a latch 304 so as to be free to pivot about an axis spaced above but parallel to cam 242 of the size control wheel 246. Above latch 304 and engaging it is a resilient spring 308 fixed to projecting part 306 of member 238. On the end of shaft 240 of lens size control wheel 244 is a small cam 314. As illustrated in FIGURE 1, with the lens supporting head 144 in its operating position, the latch 304 rides the portion of surface 310 of latch 302 above its notch 312. However, as the head 144 is rocked to its raised, inoperative position by engagement of follower 266 in recess 254 of cam 252, its notch 312 is drawn across latch 304 which by the action of spring 308 immovably engages therein so that the head cannot be further raised. Cam 314 is so arranged that through the normal range of lens sizes, it will engage in a correspondingly shaped portion of the under side of catch 304 and so is held immobile. Dislodgment of catch 304 from notch 312 in latch arm 302 is obtained by means of a pin 316. Said pin 316 is freely rotatable on the end of shaft 240 of the lens size control wheel 246. Semicircular cam 314 is so arranged on the end of shaft 240 that by rotating wheel 244 so as to lower the contact shoe 218 to a position where it would cause lenses to be edged of larger than usual diameters, cam 314 will also be moved out of its engagement within said recess on the under side of catch 304. At the same time it will have engaged pin 316 and rotated it against the lower end of latch arm 302. In the now relaxed state of catch 304, latch arm 302 can be moved by said pin 316 away from catch 304. Catch 304 therefore drops free of the receiving notch 312 and thereafter the lens spindle supporting head 144 can be raised to release follower 266 from notch 256 in cam wheel 252. It'also can be lowered to return the head to locate a lens supported by its spindles 154, 158 in position for a subsequent edging operation. Consequently latch arm 302 serves not only to limit the upward movement of the head. 144 as it is being power driven by motor 176 to an out-of-reach position but it will be appreciated also that since latch arm 302 can be disengaged from catch 304 only by turning the size-control wheel 244 so as to locate the contact shoe 218 for producing larger than usual diametered lenses, no harm will be done should the operator later forget to reset the size control. The lens Will be edged too large but this can be corrected by re-edging.

If head 144 is left free to swing about its vertical axis VAVA or VA-VA', as the case may be, the lens L will tend to ride between the frusto-conical surfaces 204, 106 of the abrading discs and the resultant bevel will be disposed with its apex substantially midway of the two lens surfaces. If it is desired that the apex of the bevel be other than so centered, this can be accomplished by introducing a force to resist free swing of the head 144 about its vertical axis. Such means comprise a quadrant member 322 secured to the right hand upper edge of the supporting plate 134, as illustrated in FIGURE 3. Referrring now to FIGURE 6, a lever arm 326 is pivotally connected at 328 to the rear side of said quadrant 322 so that it may be aligned with any one of the indicia comprising scale 324 along the arcuate edge of quadrant plate 322. A pair of springs 330 have their one end connected to adjacent the upper end of said lever arm 326 and have their opposite end connected by appropriate means such as a strap 332 to pivot-bearing member 106 of the upright support or column 88. Adjusting the position of arm 326 along the arcuate curvature of quadrant 322 will thus after the tension of springs 330 to introduce a force to counteract the free pivot of head 144 about axis VAVA and so as to alter the location of the bevel being grounded on the lens L. The upper end 327 of arm 326 is externally threaded and is provided with a slot 329 to receive said arcuate edge of the quadrant plate. Threadedly connected on said end 327 is a cap 332 which when tightened causes the parts of end 327 to either side of the slot to be drawn together to clampingly engage the quadrant. By loosening cap 332, lever arm 326 may be set at any one of a plurality of selected positions along the arcuate curvature of the quadrant 322 to introduce a desired counteracting force to the horizontal swing of head 144 and is maintained by re-tightening cap 332.

Means are also provided whereby the downward pressure with which the lens is fed into the bite of the cutting edges 204, 206 of the abrading discs may be adjusted. This is accomplished by means of a lever arm 334 pivotally connected at 336 to the rear side of a quadrant 338 generally similar to quadrant 322 but fixed to the left hand upper edge of plate 134 as viewed in FIGURE 3. Referring again to FIGURE 6, considered with FIG- URE 1, lever arm 334 is similarly adjustable about its connection 336 to vary the tension of springs 350 to which it is connected by a suitable linkage arrangement. Such comprises a first link 340 connected to arm 334 adjacent its upper end, link 340 being pivotally connected to a second link 342 to which is fixed a shaft 344 extending through a suitable opening provided. Said opening constitutes a bearing therefor in plate 134 so that movement of arm 334 will effect rotation of shaft 344 to turn a further link 346 located on the forward side of plate 134 which in turn is pivotally connected to one end of a link 348 having its other end connected to one end of the aforementioned springs 350, the opposite end of springs 350 are clip means 352 (FIGURE 1). The upper end 330 of lever arm 334, like 326, is also bifurcated on its under side so as to straddle the arcuate curved side 354 of quadrant 338 and is externally threaded so that a cap 356 may be tightened thereon to hold arm 334 in any one of several positions to which it may be adjusted along arcuate edge 354. Appropriate stops are also provided at 358 on quadrant 322 and at 360 on quadrant 338 to limit the arc through which the respective lever arms 326 and 334 may be pivoted.

Means are also provided for limiting the are through which the head 144 may be rotated about its pivotal axis (FIGURE 1). Such means comprise a member 362 fixed to the rear side of plate 134 so as to move therewith. Secured to wall 28 of the base is a member 364 having a pair of spaced upright arms 366 each having an abutment 368 disposed on the inner side of said uprights and facing each other, member 362 depending therebetween. Each of said abutments has a stem 370 by which it is threadedly connected to a respective upright 366 which allows for adjusting the spacing between abutments 368 and thereby the extent of the are through which head 144 may swing about its pivotal connections at 136 (axis VAVA of FIGURE 4 or VAVA' of FIGURE 5).

Although any convenient and conventional means may be employed for applying coolant or other lubricant to the abrading discs 24, 26, in accordance with the illustrated embodiment of the invention, a sponge 372 moistened with coolant is supported by holder 374 under the tension of spring 376 against the lower edge of the rotating discs so that the cutting edges or surfaces 204, 206 of said discs are constantly wetted by the coolant. However, there is no splattering or spattering as where the coolant is fed directly to a rotating abrading wheel from a jet. To replenish the sponge 372, coolant may be caused to slowly drip from a tap such as indicated at 378.

At this point it may be in order to briefly review the operation of the several components which comprise a machine used for bevelling the edge of the lens in accordance with the present invention. Head 144 will normally be in its up position with latch 288 caught in the notch 296 of latch 298. To insert a lens between holders 156 and 162, handle 170 will be turned to retract shaft 164 sufficiently to separate holder 162 on spindle 158 from holder 156. Lens L will be positioned with its geometrical axis on the axis of spindles 154 and 158 and with its concave side to the right of FIGURE 3, that is toward the high side of the axis about which abrading discs 24, 26 rotate. Handle 170 on shaft 164 will then be tightened until the lens is firmly positioned. A pattern 208 of the proper shape will be seated on the end of spindle 154 as by locating it over portion 210 and pins 212. Wheel 244 will be adjusted to locate contact shoe 218 at a height which will allow the lens to be edged to the required size. The abrading discs 26, 24 are assumed to be continuously rotating, one clockwise and the other counter clockwise, and the motor 176 is assumed to be connected to a source of power. Therefore, grasping the head by means of handles 294 and while depressing on finger press 286 of arm 264, first to move portion 288 of latch 290 out of notch 296 in latch 298, then to hold follower 266 from engaging in notch 254 of cam wheel 252, the operator will lower the head 144 until the periphery of lens L engages between the surfaces or cutting edges 204, 206 of the two abrading discs. In this initial position, cam follower 266 will engage the surfaces of cam wheel 252 immediately behind or above its notch 254 so that it will not catch in the notch until the cam wheel has completed a full revolution. Moving head 144, as thus described, will disengage its rear surface with roller 230 so that switch 228 closes. However, until the portion of the lens periphery thus positioned between the abrading surfaces of discs 24, 26 has been ground to size, pattern 208 will remain out of engagement with arm 222 of the contact shoe and therefore motor 176 will not operate. As soon as this portion of the lens periphery has been ground sufficiently that the former 208 engages arm 222, switch 220 will close to energize the motor and the lens will be rotated just sufficiently to present its adjacent unground portion of the lens to the abrading surfaces 204, 206 of the abrading discs. As the lens is thus rotated, head 144 will be rocked upwardly to lift the pattern 208 off arm 222, thus opening switch and stopping further rotation of lens L. The lens periphery will be rough ground to the size and shape determined by the pattern 208 and height of contact shoe 218. However, the edging of the lens periphery will continue through one or more revolutions depending on the ratio of gears 258, 256, that is until the cam wheel has again been rotated to a position where cam follower 266 will drop into notch 254. Lever arm 264 which carries follower 266 at this point will also depress rod 274 so as to close switch 268. The motor 176 will therefore continue to turn cam wheel 252 so as to rock head 144 about shaft to raise the lens L away from abrading discs 24, 26. As soon as the head 144 has been rocked through a sufficient angle that its rear wall engaging roller 230 will cause switch 228 to open, the motor will stop. At the same time as the forward or lens spindle carrying end of the head 144 is being raised away from the abrading discs, the surface 310 of latch arm 302 will run along catch 304. This also occurs during rocking of the head 144 during the actual edging of the lens. However, as the head is thus raised toward its inoperative or out-of-reach position, a point is reached where catch 304 engages in notch 312 of the latch arm 302. This halts further rise of the forward end of the head 144 and is arranged to occur simultaneously or immediately after switch 228 is opened. Thus latch 302 serves to brake any further rise 13 of the head although flexible spring 308 does allow a limited variation between the time when the catch 304 engages in notch 312 and switch 228 is closed. Latch arm 302 also serves to lock the head 144 in its up or outof-reach position so that it cannot be unlocked except and until the size control wheel 244 has been adjusted through a larger than normal range of lens sizes. This move ment of wheel 244 effectively moves the semi-circular cam 314 out of its engagement with the recess on the under side of catch 304 and also causes said cam 314 to move pin 316 into a position where it will push the latch arm 302 out of its engagement with catch 304. Head 144 may be then raised by the operator lifting on handles 294 and depressing portion 286 of the lever arm 264 so as to catch portion 288 of latch arm 290 in notch 296 and allow the lens L to be removed as turning handle 170 to retract shaft 164 and thereby spindle 158.

It will be appreciated that as the machine is used the abrading discs will wear and means must therefore be provided to compensate for this wear. For this purpose, horizontal axis HA-HA about which the head rocks may be lowered to accommodate the now smaller diametered abrading discs. This is conveniently obtained by turning disc wheel 122 at the top of column 88, which has the effect of threading stern 120 further into the bore 126 of upright 92. Wheel 122 may be provided with a scale which will be useful to indicate the extent of said adjustment. Before turning wheel 122, set screw 130 in lock nut 128 will of course be retracted and after the adjustment has been completed, it will be retightened. To recenter the lens L with respect to the high point between surfaces 204, 206 of the abrading discs, bolts 98 may be loosened in order to permit moving mounting plate 94 sufficiently to realign axis VA or VA about which plate 134 swings on its connection with the pivot bearing member of column 88. Scale 100 and index 102 may be utilized to measure the extent of adjustment.

The inclination of surfaces 206, 204 of abrading discs 24, 26 is also subject to change through wear and means are also provided whereby these angles may be trued as the need arises. These means will now be described.

Referring therefore to FIGURES 11 and 12 a stone is indicated at 380 having cutting edges 382 and 394 inclined at an angle corresponding to the included angle to be maintained between surfaces 204 and 206 of the abrading discs. Appropriate means such as the illustrated clamping device 386 may be used to immobly fix the stone to the upper surface of a first slide member 388 keyed with a guide member 390 which in turn is fixed to a second slide member 392 angularly disposed to the first slide member. The second slide membed is keyed so as to slidingly engage about a second guide member 394 mounted on all L-shaped support 396. One leg 389 of said support 396 is slotted at 400 so that it may engage about a cylindrical shaft 402 provided on the front wall 404 of the base 20. Said front wall 404 is also provided with an abutment 406 having an inclined surface 408 with which edge surface 410 of support 400 engages. Means are provided at 412 (FIGURE 2) which may be tightened on shaft 402 to hold the support 396 in place on wall 404 of the base. Surface 408 of abutment 406 is inclined so as to define a plane perpendicular to the vertical plane in which the axis of the abrading disc lies and so that slide member 388 will move along its guide 390 at an angle inclined to parallel the inclination of said axes of the abrading disc. Considered in horizontal plan, edge 384 of the stone 380 is arranged parallel to the direction in which member 388 moves along said inclined path. The second slide member 392 and its guide member 394 are so disposed that the direction of movement of slide member 392 is parallel to the side 382 of stone 380. Any appropriate means may be utilized for adjustably feeding slide members 388 and 392 along their respective guides 390 and 394. As illustrated in FIGURE 12, such means may comprise a threaded stem 414 which threads into an appropriately threaded bore 416 in one end of guide 390. The other end of stem extends through an apertured portion 418 of slide 388, a collar 420 being fixed on stem 414 to engage one side of apertured portion 418 and a handle 422 having a bore 424 to receive the protruding end of stem 414 to which it is connected as by set screw 426. Handle 422 may be provided with a cross arm as at 428. Therefore in accordance with which direction handle 422 is turned, stem 414 may be threaded into or out of bore 416 in guide 390 to correspondingly adjust slide 388 lengthwise of said guide. Adjustment of slide member 492 lengthwise of its guide 394 may be obtained by rotating handle 422 which is operatively connected to guide 394 in a similar manner. 'It will be recognized, therefore, that truing of the surfaces 204, 206 of the discs may be conveniently obtained and with a minimum of set up required. The L-shaped support 396 is simply put in place by loosening means 412 to allow slot 400 to fit over shaft 402. The edge 410 of said support will engage surface 408 which will align surfaces 382 and 384 of the stone 380 with the surfaces 204 and 206 of the abrading discs. The stone may be then fed against said surfaces by first rotating either handle 422 or 422' and then the other which assure a proper truing of the abrading surfaces.

In the embodiments of the inventions as thus far described, means are provided in the form of a lever arm 302 pivotally connected at 303 to the forward end of the lens spindle supporting carriage 144 and provided with a notch 312 which engages with a latch 304 to releasably lock the carriage in the position to which it is raised at the conclusion of the edging cycle. Means in the form of a cam 314 and pin 316 are provided which disengage latch 304 from notch 312 when wheel 244 is turned to a large lens size setting. This has been described as providing the advantage that it minimizes the opportunities the operator has for edging a lens too small because of his failure to reset the control wheel 244 between edging operations. FIGURES 13 and 14 show an alternate arrangement wherein the carriage is not locked in its raised position at the end of the edging cycle but the lens size control mechanism is automatically reset to a maximum lens size at said time to that many of the same advantages are obtained.

Thus, referring to said FIGURES 13 and 14, a toothed wheel 450 is fixed about shaft 240 of the lens size control wheel 244 to turn therewith as wheel 244 is rotated to raise and lower cam 242 which adjusts the height of contact shoe 218 in relation to the former 208 and by means of which the size of the lens L is set. Associated with toothed wheel 450 is a spring 452 which is tensioned to urge the toothed wheel 450 to rotate the control wheel 240 and its cam 242 to locate the contact shoe at a spacing from the former 208 to accommodate the largest lens size. The action of spring 452 is however opposed by a pawl 454 pivotally connected at 456 on an upstanding portion 458 welded, integrally formed or otherwise secured to supporting member 246, the free end 460 of the pawl being shaped to engage in the teeth of wheel 450. Rigidly fixed to the forward end of the carriage as by means 462 is a trip lever 464 having a piece 466 projecting from its lower end to engage a projecting part 468 on the free end 460 of the pawl. Said piece 466 is pivotally connected to trip lever 464 so that it is free to swing upwardly in the provided slot 470 but is restrained by part 472 from dropping below the illustrated horizontal position. Therefore at the completion of the edging cycle and as cam 252 acts on portion 266 of lever 264 to effect rocking of the carriage 144 about axis HA of shaft 142, the raising of the forward end of the carriage causes piece 466 to engage projection 468 and disengage the pawl from between the teeth of wheel 450. Thereupon spring 452 rotates cam 242 and lens size control wheel 244 to locate the contact shoe 218 for a maximum lens size setting. The radius through which piece 466 swings about axis HA, in the raising of carriage 144, is several times longer than the radius or distance which separates projection 468 on the pawl from its pivot 456. Consequently as the carriage is raised, a point is reached where piece 466 swings away from projection 468, allowing the pawl 454 to drop back to engage the toothed periphery of wheel 450.

Control wheel 244 may be then reset for a desired lens size, the rotation of wheel 244 effectively cocking spring 452, and pawl 454 again swinging to hold wheel 450 against the action of the now cocked spring 452. When the carriage 144 is again lowered to locate its lens L in position to engage abrading discs 24, 26, the aforedescribed pivotal mounting of piece 466 allows it to move past projection 468 on the pawl without disengaging the pawl 454 from wheel 450. It will be understood of course that the length of trip lever 464 is suificient that piece 466 is located a distance sufliciently below the pawl projection 468 that it does not engage said projection during the limited rocking of the carriage which takes place during the actual edging operation itself and only engages with said projection as the carriage is being raised to its rest position at the end of the edging cycle.

From the foregoing description of the preferred forms of the invention it will be recognized that all of the recited features, objects and advantages of the invention have been demonstrated as providable in a machine of entirely practical, simple and economical construction.

Thus, having described the invention, I claim:

1. In machines for edging work such as a lens, the combination of rotatable abrading means, a work supporting head movable between a working position and an inoperative position, a rotatable holder on said head adapted to support work such as a lens in edgewise engagement with the abrading means when the head is in its working position, a pattern to turn with the holder during the edging operation, a contact shoe for engagement by the pattern to control the depth to which the work is edged by the abrading means, a rotatable carn engaging said shoe and adapted by its rotation to move the shoe toward and away from the pattern, the position of the shoe determining the size of the work to be edged, means which move said head to its inoperative position after the work has been edged, a catch carried by said head, locking means associated with said rotatable cam with which the catch engages when the head is raised to its said inoperative position to releasably hold the head in said position, said locking means being released by the catch means when the rotatable cam is thereafter rotated to move the contact shoe toward the pattern.

2. In machines for edging work such as a lens, the combination of rotatable abrading means, a work supporting head movable between a working position and an inoperative position, a rotatable holder on said head adapted to support work such as a lens in edgewise engagement with the abrading means when the head is in its working position, a motor to turn said holder, a pattern to turn with the holder during the edging operation, a contact shoe for engagement by the pattern to control the depth to which the work is edged by the abrading means, said shoe being adjustable toward and away from the pattern in accordance with the size of the work to be edged, means operated by said motor which move said head to its inoperative position after the work has been edged, means which are engaged by said head in its inoperative position to deenergize the motor, the head having catch means and the shoe having abutment means associated therewith and with which the catch means interlock when the 'head is raised to its said inoperative position to hold the head in said position, said abutment means being caused by adjustment of the contact shoe toward the pattern to release its hold on said catch means.

3. In machines for edging work such as a lens, the combination of a base, abrading means rotatably mounted on said base, a work Supporting head mounted on said base over the abrading means, a rotatable holder on said head adapted to support work such as a lens in edgewise engagement with the abrading means, said head being rockable about a horizontal axis spaced rearwardly of said work holder, a pattern to turn with the holder during the edging operation, a contact shoe located below said pattern for engagement by the pattern to control the depth to which the work is edged by the abrading means, said shoe being adjustable on said base toward and away from the pattern in accordance with the size of the work to be edged, means to rock said head at the completion of the edging of the work to raise the work away from the abrading means, a latch on said head, a catch on said base adapted to engage said latch when the head has been rocked through a predetermined angle so as to lock the head with the holder in a raised position away from the abrading means, and means actuable by adjusting the shoe toward the pattern to release the hold of said catch on the latch.

4. In machines for edging work such as a lens, the combination of a base, abrading means rotatably mounted on said base, a work supporting head mounted on said base to swing about a horizontal axis, an axially rotatable holder on said head spaced forwardly of said horizontal axis and adapted to support work such as a lens in edgewise engagement with the abrading means, means including a motor to turn the holder, a pattern to turn with the holder during the edging operation, a contact shoe located below said pattern including a make and break switch to energize the motor when engaged by the pattern to control the depth to which the work is edged by the abrading means, said shoe being adjustable on said base toward and away from the pattern in accordance with the size of the Work to be edged, means driven by said motor to rock said head at the completion of the edging of the work through an angle sufficient to raise the work away from the abrading means, a latch on said head a catch on said base adapted to engage said latch when the head has been rocked through a predetermined angle so as to lock the head with the holder in a raised position away from the abrading means, means for deenergizing the motor when the head has been rocked to said raised position of the holder, and means actuable by raising the pattern to release the hold of said catch on the latch.

5. In machines for edging work such as a lens, the combination of a base, abrading means rotatably mounted on said base, a work supporting head mounted on said base to swing about a horizontal axis, a rotatable holder mounted on said head forwardly of said horizontal axis and adapted to support work such as a lens in edgewise engagement with the abrading means, a pattern to turn with the holder during the edging operation, a contact shoe located below said pattern for engagement by the pattern to control the depth to which the work is edged by the abrading means, a rotatable shaft having means associated with said shoe which are operated by rotation of said shaft to adjust the shoe toward and away from the pattern in accordance with the size of the work to be edged, means to rock said head at the completion of the edging of the work to raise the work away from the abrading means, a latch arm pivotally connected to the forward portion of said head and having a notch in its side adjacent its lower end, a catch on said base adapted to ride said side of said latch arm and to engage in the notch of said latch arm when the head has been rocked through a predetermined angle so as to lock the head with the holder in a raised position away from the abrading means, and means actuable by rotation of said shaft to raise the contact shoe which releases the hold of the catch on the latch arm so as to permit lowering of the head to locate work supported by the holder in position for edging by the abrading means.

6. A lens edging device comprising rotatably mounted abrading means, a head disposed above said abrading means and having means for rotatably supporting a lens 1n edgewise engagement with said abrading means, said head being mounted to swing about a horizontal axis spaced from said lens supporting means, a motor adapted to turn said lens supporting means so as to present the full periphery of said lens to the abrading means for the edging operation, a cam mounted to turn about said horizontal axis, means drivingly connecting the motor to the cam so as to turn the cam as the lens supporting means turns, a notch in the periphery of said cam, means mounted on said head having a part on the side of said horizontal axis opposite to that of the lens supporting means, said part riding the periphery of the cam so as to be caught in said notch, said cam being turned by the motor to catch the follower in its notch as the notch is being moved downwardly away from a vertical plane containing said horizontal axis so as to rock the head about the horizontal axis to raise the lens supporting means to an inoperative position above and away from the abrading means.

7. A lens edging device comprising rotatably mounted abrading means, a head disposed above said abrading means and having means for rotatably supporting a lens in edgewise engagement with said abrading means, said head being mounted to swing about a horizontal axis spaced from said lens supporting means, a motor adapted to turn said lens supporting means, so as to present the full periphery of said lens to the abrading means for the edging operation, a cam mounted to turn about said horizontal axis, means drivingly connecting the motor to the cam so as to turn the cam as the lens supporting means turns, a notch in the periphery of said cam, means mounted on said head having a part on the side of said axis opposite to that of the lens supporting means, said part riding the periphery of the cam so as to be caught in said notch, said cam being turned by the motor to catch the follower in its notch as the notch is being moved downwardly away from a vertical plane containing said horizontal axis so as to rock the head about the horizontal axis to raise the lens supporting means to an inoperative position above and away from the abrading means and switch means located to be actuated by raising of said head to deenergize the motor when the head has thus been rocked through an angle sufficient to raise the lens supporting means to said inoperative position.

- 8. A lens edging device comprising rotatably mounted abrading means, a head disposed above said abrading means and having means for rotatably supporting a lens in edgewise engagement with said abrading means, said head being mounted to swing about a horizontal axis spaced from said lens supporting means, a motor adapted to turn said lens supporting means so as to present the full periphery of said lens to the abrading means for the edging operation, a cam mounted to turn about said horizontal axis, means drivingly connecting the motor to the cam so as to turn the cam as the lens supporting means turns, a notch in the periphery of said cam, means mounted on said head having a part on the side of said horizontal axis opposite to that of the lens supporting means, said part riding the periphery of the cam so as to be caught in said notch, said cam being turned by the motor to catch the follower in its notch as the notch is being moved downwardly away from a vertical plane containing said horizontal axis so as to rock the head about the horizonal axis to raise the lens supporting means to an inoperative position above and away from the abrading means, switch means located to be actuated by raising of said head to deenergize the motor, and means for releasably locking the head in said raised position.

9. In a device for edging lenses, the combination of a base, abrading means rotatably supported on the base, a head including rotatable means for supporting work such as a lens over the abrading means and in edging engagement therewith, supporting structure on said base to the rear of the abrading means, said head being supported on said supporting structure to rock about a horizontal axis and to swing about a vertical axis spaced behind said horizontal axis, a pair of spaced sector plates rigidly supported on said supporting structure at convenient locations to the rear of said head, a radial arm pivotally connected to adjacent the intersection of the two sides of each said sector plates, a first tensioning means connected between one of said radial arms and the center area of supporting structure, a second tensioning means connected between the front portion of said head and the radial arm of the other sector plate, the first radial arm being adjustable about its sector plate to provide a variable tension on the swinging of the head about its vertical axis and the other radial arm being adjustable about its sector plate to alter the force with which the head urges the edge of the work to the abrading means, each said radial arms further having locking means associated with its respective sector plate for securing it in an adjusted position on the sector plate.

10. In a device for edging lenses the combination of a base, abrading means rotatably supported on the base, a head including rotatable means for supporting work such as a lens over the abrading means and in edging engagement therewith, supporting structure on said base to the rear of the abrading means, said head being supported on said supporting structure to rock about a horizontal axis and to swing about a vertical axis spaced behind said horizontal axis, a pair of quadrant plates rigidly supported on said supporting structure at conveniently spaced locations above and to the rear of said head on opposite sides of the vertical axis about which the head swings, a radial arm pivotally connected to adjacent the intersection of the two sides of each said quadrant plates, a first tensioning means connected between the outer end of one said radial arms and the supporting structure intermediate the two quadrant plates, a second tensioning means connected between the front portion of said head and motion amplifying linkage means associated with the radial arm of the other quadrant plate, the first radial arm being adjustable about its quadrant plate to provide a variable tension on the swinging of the head about its vertical axis and the other radial ar-m being adjustable about its quadrant plate to alter the force with which the head urges the edge of the work to the abrading means, each said radial arms further having locking means associated with its respective quadrant plate for securing it in an adjusted position on the quadrant plate.

11. In a device for edging lenses the combination of a base, abrading means rotatably supported on the base, a head including rotatable means for supporting work such as a lens over the abrading means and in edging engagement therewith, supporting structure on said base to the rear of the abrading means, said head being supported on said supporting structure to rock about a horizontal axis and to swing about a vertical axis spaced behind said horizontal axis, a first and a second radial arm' each pivotally connectd to said supporting structure to swing about a horizontal axis normally disposed to the horizontal axis about which the head swings and on opposite sides of the vertical axis about which the head swings, a first tensioning means connected between the outer end of one said radial arms and the supporting structure intermediate the pivotal connections of said radial arms and behind the vertical axis about which the head swings, a second tensioning means connected between the front portion of said head and motion amplifying linkage means associated with the other radial arm, the first radial arm being adjustable about its horizontal axis to vary the tension on the swinging of the head about its vertical axis and the other radial arm being adjustable about its axis to alter the force with which the head urges the edge of the work to the abrading means, and locking means associated with each said radial arms for securing it in an adjusted position about its axis.

12. A device for edging lenses comprising a pair of unequal-diametered superposed abrading discs mounted to rotate about inclined coincident axes and in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having its outer edge surface of frusto-conical shape, the protruding margin of the side of the larger disc facing the first disc being on a slight bevel, and an optical head including means for supporting work such as a lens with its edge between said frusto-conical outer edge of the first disc and beveled outer margin of the other disc, said supporting means being mounted on said head to turn about a generally horizontal axis, and said head being swingable about a pair of angularly disposed axes disposed at a distance from the horizontal axis about which the supporting means turns, one of said axes being vertically disposed and the other one of said axes being disposed intermediate said vertically disposed axis and the generally horizontal axis about which the work supporting means turns.

13. A device for edging lenses comprising a pair of unequal-diametered superposed abrading discs mounted to rotate about inclined coincident axes and in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having its outer edge surface of frustoconical shape, the protruding outer margin of the side of the other disc facing the first disc being on a slight bevel, an optical head including means for supporting work such as a lens with its edge between said frusto-conical outer edge of the first disc and the beveled outer margin of the other disc, said supporting means being mounted on said head to turn about its own axis which is generally horizontally disposed, and said head being swingable about a pair of right-angularly disposed axes, one of said axes being vertically disposed at a distance from the horizontal axis about which the supporting means turns which approximates the radii of the abrading discs, the other one of said axes being disposed intermediate said vertical axis and the axis about which the work supporting means turns.

14. A device for edging lenses comprising a pair of unequal-diametered superposed abrading discs mounted to ratate about inclined coincident axes and with their inboard sides in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having its outer edge surface of frustoconical shape, the outer annular margin of the side of the other disc facing the first disc and protruding therebeyond being on a slight bevel, an optical head including means for supporting work such as a lens with its edge between said frusto-conical outer edge of the first disc and beveled outer margin of the other disc, said head being swingable about a vertically disposed axis which permits centering of the edge of the work between said beveled margin and frusto-conical edge of the two discs, said head being also swingable about a horizontal axis which permits gravitational feeding of the work into the edging action between the abrading discs, the supporting means being rotatable about its own axis so as to present all of the periphery of the work to the abrading action of said two discs, a motor drivingly connected to said supporting means to effect rotation thereof, means driven by said motor simultaneous with its rotation of the supporting means which rock the optical head about its horizontal axis through an angle sufficiently large to raise the supporting means well above the abrading discs.

15. In a device for edging lenses comprising a base, a pair of unequal-diametered superposed abrading discs mounted on said base to rotate about inclined coincident axes, said discs being supported with their inboard sides in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having an outer edge surface of frusto-conical shape inclined toward its inboard side, the other disc having the outer margin of its inboard side extending beyond the first disc and inclined toward the outer surface of the smaller-diameter disc means detachably secured to said base including a first member supported so as to be adjustable toward and away from a vertical plane including said axes of the abrading discs, a second member mounted on said first member so as to be adjustable through an inclined plane normal to the vertical plane which includes the axes of the abrading discs and is parallel to said axes, a cutting stone supported on said second member having a pair of angularly related surfaces one to engage the frusto-conical outer edge of the smaller diameter abrading disc and the other to engage the inclined outer margin of the inboard side of the longer diameter disc, said second member being slidably adjustable on the first member to align the cutting stone with said surfaces of the abrading discs, and the first member being slidably adjustable to feed the cutting stone into engagement with said surfaces of the two abrading discs.

16. In a device for edging lenses comprising a base having a forward vertical wall, a pair of unequal-diametered superposed abrading discs mounted on said base behind said wall to rotate about inclined coincident axes paralleling said wall, said discs being supported with their inboard sides in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having an outer edge surface of frusto-conical shape inclined toward its inboard side, the other disc having the outer margin of its inboard side extending beyond the first disc and inclined toward the outer surface of the smaller-diameter disc defining an included angle therebetween, an angle plate having one portion detachably secured to said forward vertical wall of the base and having a second portion with a planar surface inclined at an angle corresponding to the angle at which said axes of the abrading discs are disposed, a first member slidably supported on said planar surface so as to be adjustable toward and away from a vertical plane including said axes of the abrading discs, a second member mounted on said first member so as to be adjustable through an inclined plane normal to the vertical plane which includes the axes of the abrading discs and parallel to said axes, a cutting stone supported on said second member having a pair of angularly related surfaces corresponding to the included angle between the frusto-conical outer edge of the smaller diameter abrading disc and the inclined outer margin of the inboard side of the longer diameter disc, said second member being slidably adjustable on the first member to align the cutting stone with said surfaces of the abrading discs, and the first member being slidably adjustable to feed the cutting stone into engagement with said surfaces of the two abrading discs.

17. For use in a device for edging lenses comprising a base having a forward vertical wall, a pair of unequaldiametered superposed abrading discs mounted on said base behind said wall to rotate about inclined coincident axes, paralleling said wall, said discs being supported with their inboard sides in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having an outer edge surface of frusto-conical shape inclined toward its inboard side, the other disc having the outer margin of its inboard side extending beyond the first disc and inclined toward the outer surface of the smaller-diameter disc to define an included angle therebetween; and angle plate having one portion adapted for detachable mounting on said forward vertical wall of the base and having a second portion projecting forwardly therefrom at right angles and inclined at a transverse angle corresponding to the angle at which said axes of the abrading dlSCS are disposed, a first member slidably supported on 21 said second portion in said angular relation, means adapting said first member for adjustment in a direction toward and away from a vertical planeincluding said axes of the abrading discs, a second member mounted on said first member so as to be adjustable through an inclined plane normal to the vertical plane which includes the axes of the abrading discs and parallel to said axes, a cutting stone supported on said second member having a pair of angularly related surfaces corresponding to the included angle between the outer edge of the smaller diameter abrading disc and the inclined outer margin of the inboard side of the longer diameter disc, said second member being slidably adjustable on the first member to align the cutting stone with said surfaces of the abrading discs, and the first member being slidably adjustable to feed the cutting stone into engagement with said surfaces of the two abrading discs.

18. A device for edging lenses comprising a base, abrading means rotatably mounted on said base, a head having means for rotatably supporting a lens in edgewise engagement with said abrading means, said head being mounted on said base to swing about a horizontal axis disposed to the rear of said lens supporting means, a motor to turn said lens supporting means, a former to turn with said lens supporting means, a make and break switch located for operation by said former to permit starting and stopping of said motor in order toedge the lens in one full turn of the lens supporting means, a cam mounted to turn about said horizontal axis, means drivingly connecting the motor to the cam so that it turns as the lens supporting means turns, a notch in the periphery of said cam, a follower pivotally mounted on said head to the forward side of said horizontal axis and having a portion to ride the periphery of said cam, said follower portion being of a shape to engage in and be caught by said notch, and said portion of the follower being located to the rearward side of said horizontal axis and the cam so that when caught in the notch of the cam, the cam will rock the head about the horizontal axis to raise the lens supporting means to an inoperative position above and away from the abrading means, and a normally closed switch located to be opened by raising of said head to deenergize the motor and stop further turning of the lens supporting means.

19. A device for edging work such as lenses comprising rotatable abrading means, a head positioned over said abrading means and movable between a working position ,and a rest position, a rotatable holder on said head adapted to support work in edgewise engagement with the abrading means, said work holder being movable toward and away from the abrading means when the head is in its working position, an electric motor to turn the work holder, a pattern mounted to turn with the work holder, a

shoe positioned below said pattern, a motor circuit including a first normally open switch located tobe closed by engagement of the pattern with the shoe as the work holder moves toward the abrading means in response to grinding away of a peripheral portion of the supported work by the rotating means, closing of said switch energizing the motor to turn the work holder to locate an adjacent peripheral portion of the supported Work for edging by the abrading means whereby the work is edged to the shape of the pattern in one revolution of the work holder, cam means driven by said motor simultaneously with its turning of the work holder, said cam means being turned at a rate slower than the work holder is turned by the motor so that the work holder completes more than one revolution while the cam makes one revolution, the cam means having means associated therewith to move the head out of its working position when it makes one revolution, a second normally open switch in said motor circuit in parallel to said first switch, means actuated by said cam means as it starts to move the head out of its working position to close said second switch to allow-the motor to continue to turn ing means, said work holder being movable toward and away from the abrading means when the head is in its working position, an electric motor to turn the work holder, a pattern mounted to turn with the work holder, a shoe positioned below said pattern, a motor circuit including a first normally open switch located to be closed by engagement of the pattern with the shoe as the work holder moves toward the abrading means as a peripheral portion of the supported work is ground away by the rotating means, closing of said switch energizing the motor to turn the work holder to locate an adjacent peripheral portion of the supported work for edging by the abrading means whereby the work is edged to the shape of the pattern in one revolution of the work holder, cam means driven by said motor simultaneously with its turning of the work holder, said cam means being turned at a rate slower than the work holder is turned by the motor so that the work holder completes more than one revolution while the cam makes one revolution, means associated with the cam means to move the head out of its working position as the cam means completes one revolution, a second normally open switch in said motor circuit in parallel to said first switch, means actuated by said cam means as it starts to move the head out of its working position to close said second switch as the movement of the pattern from the shoe opens the first switch so that the cam means will continue to move the head to its rest position, a third normally closed switch in said motor circuit in series with said first two switches which is actuated by movement of the head into its rest position to deenergize the motor, and means operable to permit returning of the head to its working position.

21. A device for edging lenses comprising a base, abrading means rotatably mounted on said base to turn about an inclined axis, bracket means supported by said base to swing about a vertical axis, a head supported on said bracket means to swing about a horizontal axis, a work holder rotatably mounted on said head forwardly of said horizontal axis to turn about its own axis disposed parallel to said horizontal axis, said work holder being adapted to support work such as a lens in edgewise engagement with the rotatable abrading means, a motor carried by said bracket, a gear train connecting the arbor of said motor :to said lens holder to turn the holder when the mot-or is energized, means supporting a former at one end of said work holder to turn with the holder and work supported thereby, a contact shoe including a normally open switch in the electrical circuit of the motor, said shoe being positioned to be engaged by the former as a peripheral portion of the work is ground down to a size determined by the contact shoe, said engagement of the shoe by the former closing said switch to allow the motor to rotate the work holder through an angle to where the work rocks the head about its horizontal axis to raise the former out of engagement with the shoe which allows the switch to open and thereby to stop further rotation of the work holder until the former again engages the shoe, a cam mounted on said head to turn about its said horizontal axis, a first gear arranged to be driven by the motor, a second gear meshing with said first gear and connected to the cam so that as the first gear is driven by the motor the cam will turn therewith, the ratio between said first and second gears being such that the work holder is turned in excess of one revolution as the cam is turned once, said cam having an abutment on its periphery, and a follower pivotally mounted on said head having a part to ride on the periphery of the cam to the side of the horizontal axis of the head opposite to that on which the work holder is mounted, said part engaging with the abutment so that a force is exerted on the head by the cam as its abutment is moved downwardly away from a vertical axis containing the horizontal axis to swing the head about its said horizontal axis, a second normally open switch connected in the motor circuit in parallel to said first switch, means engaged by said cam follower as its part catches with the abutment of the cam to close said second switch whereby the motor will continue to turn the cam so as to swing the head through an are about its horizontal axis sufficient to raise the pattern out of engagement with the contact shoe, said cam follower being thereafter actuable to release its part from the abutment and allow the head to return the work holder and pattern to their working position with respect to the contact shoe and rotatable abrading means.

22. The device claimed in claim 21 having means for introducing tension to resist the swinging of the bracket about its vertical axis and the swinging of the head on the bracket about its horizontal means, and adjustable means for varying said tension.

23. The device claimed in claim 21 wherein the shoe is adjustable toward and away from the pattern in accordance with the size of the work to be edged, the device having locking means to hold the head in the high position to which it is raised by the cam means, and means actuatable by adjustment of the contact shoe toward the pattern to release the hold of said locking means.

24. A device for edging lenses comprising a base, abrading means rotatably mounted on said base to turn about an inclined axis, bracket means supported by said base to swing about a vertical axis, a head supported on said bracket means to swing about a horizontal axis, a work holder rotatably mounted on said head forwardly of said horizontal axis to turn about its own axis disposed parallel to said horizontal axis, said work holder being adapted to support work such as a lens in edgewise engagement with the rotatable abrading means, a motor carried by said bracket, a gear train connecting the arbor of said motor to said lens holder to turn the holder when the motor is energized, means supporting a former at one end of said work holder to turn with the holder and work supported thereby, a contact shoe including a normally open switch in the electrical circuit of the motor, said shoe being positioned to be engaged by the former as a peripheral portion of the work is ground down to a size determined by the contact shoe, which engagement of the shoe by the pattern effects closing of said switch to allow the motor to rotate the work holder through an angle to Where the work will rock the head about its horizontal axis to raise the former out of engagement with the shoe which allows the notch to open and thereby to deenergize the motor and stop further rotation of the work holder until the former again engages the shoe, a cam mounted on said head to turn about its said horizontal axis, a first gear arranged to be driven by the motor, a second gear meshing with said first gear and connected to the cam so that as the first gear is driven by the motor the cam will turn therewith, the ratio between said first and second gears being such that the work holder is turned three times for each revolution of the cam, said cam having a notch in its periphery, and a follower pivotally mounted on said head having a part to ride on the periphery of the cam, said part engaging in the notch so as to be carried by the cam as its notch is moved downwardly away from a vertical axis containing the horizontal axis to swing the head about said horizontal axis, a second normally open switch connected in the motor circuit in parallel to said first switch, means engaged by said cam follower as its part catches in the notch of the cam to close said second switch whereby the motor will continue to turn the cam so as to swing the head through an are about its horizontal axis which is suflicient to raise the pattern out of engagement with the contact shoe, and a third normally closed switch in series with the first two switches in the motor circuit, said third switch being located so as to be actuated by engagement of the head therewith to deenergize the motor when the head has been driven by the cam to locate the work holder at a desired height over the abrading means, said cam follower being thereafter actuable to release its part from the notch in order to return the work holder and pattern to their working position with respect to the contact shoe and rotatable abrading means.

25. The device claimed in claim 24 having a rotatable shaft and means associated with said shoe which are operated by rotation of said shaft to adjust the shoe toward and away from the pattern in accordance with the size of the work to be edged, a latch arm pivotally connected to the forward portion of said head and having a notch in its side adjacent its lower end, a catch on said base adapted to ride said side of said latch arm and to engage in the notch of said latch arm when the head has been rocked through a predetermined angle so as to lock the head with the holder in its raised position spaced from the abrading means, and means actuable by rotation of said shaft to move the latch arm away from the catch so as to permit lowering of the head to locate work supported by the holder in position for edging by the abrading means.

26. The device claimed in claim 25 wherein the catch is pivotally mounted and the means actuatable by rotation of the shaft comprises a cam which engages said catch to resist its turning, said cam being rotatable out of engagement with the catch when the shaft is rotated to locate the shoe at its high position, said cam having a projection which engages the latch arm when the shaft is so rotated to move the latch arm away from the catch and allow the catch to drop out of the notch therein.

27. The device claimed in claim 24 wherein the abrading means comprise a pair of unequal-diametered superposed abrading discs mounted to rotate about inclined coincident axes and with their inboard sides in juxtaposed spaced relation, one disc turning clockwise and the other disc turning counterclockwise, the upper one of said discs being of smaller diameter and having its outer edge surface of frusto-conical shape, the outer margin of the side of the other disc extending beyond the first disc being on a slight bevel.

28. The device claimed in claim 27 wherein the frustoconical outer edge of the smaller-diametered disc and the beveled outer margin of the larger-diametered disc define an inclined angle of greater than degrees.

29. In lens edging machines, the combination of rotatable abrading means, a work supporting head, a holder rotatably mounted on said head adapted to support work such as a lens in position to be edged by the abrading means, adjustable means which control the size to which the work is edged, means which move the head to an inoperative position at the end of the edging cycle, and means actuated by the movement of said head to said position which adjust the work size control means to its maximum work size adjustment at the end of the edging cycle.

30. In the lens edging machines, the combination of v rotatable abrading means, a work supporting head movable between a working position and an at-rest position, a rotatable holder on said head adapted to support work such as a lens in edgewise engagement with the abrading means when the head is in its working position, a pattern to turn with the holder during the edging operation, a contact shoe for engagement by the pattern to control the depth to which the work is edged by the abrading means, cam means for adjusting said contact shoe toward and away from the pattern in accordance with the size of the lens to be edged, means which move said head to its at-rest position after the lens has been edged, spring means urging said cam means to lower the contact shoe, latch means which resist said urging of the spring means, and trip means, actuated by movement of the work supporting head to its at-rest position which act on the latch means to release its resistance to the spring means and allow said spring means to cause the cam means to lower the contact shoe at the end of the edging cycle.

31. In a machine for edging work such as a lens, the combination of abrading means, a work supporting head rockable about an axis between a working position and an inoperative position, a work holder on said head adapted to suport work such as a lens for presentment of its periphery to the abrading means for edging when the head is in its working position, the work holder being rotatably mounted on said head in order to present the full periphery of the work with each revolution thereof, a rotatable wheel including a catch thereon, a motor, means drivingly connecting said motor to the workholder and wheel so as to simultaneously turn said work holder and wheel when the motor is energized, the wheel being turned by the motor at a rate such that the work holder is turned through at least a full revolution each time the wheel completes a revolution, said head including a part spaced from said axis about which the head is rockable and so located as to be locked by the catch to the wheel as it completes a revolution, and the motor moving the head out of its working position to its inoperative position through said locking of said catch with the part as the motor continues to turn said wheel.

32. The combination claimed in claim 31 further having means for disengaging said catch and part once the head has been moved to its inoperative positon.

33. In a machine for edging work such as a lens, the combination of abrading means, a work supporting head mounted to rock about an axis between a working position and an inoperative position, a Work holder on said head adapted to support work such as a lens for presentment of its periphery to the abrading means for edging when the head is in its working position, the work holder being rotatably mounted on said head in order to present the full periphery of the work with each revolution thereof, a rotatable wheel including a catch thereon, a motor, means drivingly connecting said motor to the workholder and wheel so as to simultaneously turn said work holder and wheel when it is energized, the wheel being turned by the motor at a rate such that the work holder is turned through at least 360 degrees each time the Wheel completes a revolution, said head including a part spaced from said axis about which the head rocks and so located as to be locked by the catch to the wheel as it completes a revolution, means actuated by the wheel causing the motor to continue to turn the wheel when said part on the head is locked to the catch, the motor moving the head out of its working position to its inoperative position through the locking of said catch with the part as the wheel continues to turn, and means deenergizing the motor as the head reaches its inoperative position.

34. The combination claimed in claim 33 further having means for disengaging said catch and part once the head has been moved to its inoperative position.

References Cited by the Examiner UNITED STATES PATENTS 2,056,182 10/3 6 Gardner 512O9 XR 2,528,137 10/50 Grasser 51--101 2,575,022 11/51 Lemay 51-101 2,651,890 9/53 Rubinstein 51-101 2,725,689 12/55 Dexter 51-101 2,748,541 6/56 Connell 51101 2,821,050 1/58 McCarthy 51101 3,011,291 12/61 Walton et al. 51--127 LESTER M. SWINGLE, Primary Examiner.

UNITED STATES PATENT OFFICE Certificate of Correction Patent No. 8,210,890 October 12, 1965 'illiam A. Lannoin It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 19, line 44, for rebate rend -rotate; after column 20, insert the following: 

1. IN MACHINES FOR EDGING WORK SUCH AS A LENS, THE COMBINATION OF ROTATABLE ABRADING MEANS, A WORK SUPPORTING HEAD MOVABLE BETWEEN A WORKING POSITION AND AN INOPERATIVE POSITION, A ROTATABLE HOLDER ON SAID HEAD ADAPTED TO SUPPORT WORK SUCH AS A LENS IN EDGEWISE ENGAGEMENT WITH THE ABRADING MEANS WHEN THE HEAD IS IN ITS WORKING POSITION, A PATTERN TO TURN WITH THE HOLDER DURING THE EDGING OPERATION, A CONTACT SHOE FOR ENGAGEMENT BY THE PATTERN TO CONTROL THE DEPTH TO WHICH THE WORK IS EDGED BY THE ABRADING MEANS, A ROTATABLE CAM ENGAGING SAID SHOE AND ADAPTED BY ITS ROTATION TO MOVE THE SHOE TOWARD AND AWAY FROM THE PATTERN, THE POSITION OF THE SHOE DETERMINING THE SIZE OF THE WORK TO BE EDGED, MEANS WHICH MOVE SAID HEAD TO ITS INOPERATIVE POSITION AFTER THE WORK HAS BEEN EDGED, A CATCH CARRIED BY SAID HEAD, LOCKING MEANS ASSOCIATED WITH SAID ROTATABLE CAM WITH WHICH THE CATCH ENGAGES WHEN THE HEAD IS RAISED TO ITS SAID INOPERATIVE POSITION TO RELEASABLY HOLD THE HEAD IN SAID POSITION, SAID LOCKING MEANS BEING RELEASED BY THE CATCH MEANS WHEN THE ROTATABLE CAM IS THEREAFTER ROTATED TO MOVE THE CONTACT SHOE TOWARD THE PATTERN. 